Moving stairway



NOV. 1, 1938 mn u sf 2,135,188

MOVING STAIRWAY Filed Feb. 11, 1938 2 Sheets-Sheet 1 :UM LMWINVENTOR BY ATTORNEY 'Nov. 1, 1938. D. LINDQUIST MOVING STAI RWAY Filed Feb. 11, 1938 2 Sheets-Sheet 2 n d E s 3 2 c 3 on h\ 8 T2 QEW Z 3 3 3 w 2 w a S L W n 'l I Q s WWTL N m 2 $5 V:

ATTORNEY Patented Nov. 1, 1938 7 2,135,188 oms STAIRWAY David Leonard Lindquist, White Plains, N. Y., assignorto Otis Elevator Company, New York, N. Y., a corporation of New Jersey Application February 11, 1938, Serial No. 189,974

6 Claims.

The invention relates to moving Stairways.

In present day moving stairway installations, it is the general practice to provide steps with curved risers and with treads having a plurality of longitudinally extending cleats; Combplates are provided at the ends of the stairway, the teeth of the combplates extending into the grooves between the cleats and being inclined upwardly therefrom to facilitate the exit of pas sengers. from the stairway. In previous constructions, the ends of the cleats facing the riser of an adjacent step are beveled back to minimize the clearance between the bottom of the cleat grooves and' the riser when the'steps are in step formation on theincline of the stairway. This constructionresults in a V-shaped slot between the ends of the cleats of adjacent steps when the steps are in platform formation and about to pass beneath the combplate.

- The invention involves eliminating the V slots between adjacent steps and providing a minimum operating clearance between the end of the tread cleats of each step and the 'riserof the adjacent step while the steps are in step formation and during their transition to platform formation. In :carrying out the invention, the ends of the cleats of each step facing the ends of the cleats of the adjacent step at the time that the steps are-in platform formation are made substantially vertical and extend up to a minimum operating distance therefrom. This provides a small clearance between theends of the treads of adjacent steps both at the top of the cleats and the bottoms of the tread grooves at the timethat the steps pass beneath the combplate. The face of the riser is provided with a plurality of vertically extending grooves to form cleats to mesh with the ends of the tread cleats of the adjacent the adjacent step as the transfer-takes place.

The size of the riser cleats with respect to the tread cleats is such as to provide a minimum operating clearance. Thus a minimum clearance is provided between the tread and the riser of the adjacent step while the steps are in step formation and this clearance is maintained during the transition of the'steps to platform formation.

Features and advantages of the invention will be apparent from the following description and appended claims.

In the drawings:

Figure 1 is a diagrammatic representation in side elevation of the upper end of a moving stair way embodying the invention;

Figure 2 is an" enlarged view, facing the riser, of one of the steps of Figure l;

V Figure 3 is a view in section, taken along the line 3-3 of Figure 2, showing the construction of the riser of the step shown in Figure 2 and also illustrating the adjacent step both in step and platform formation with respect thereto;

and

Figure 4 is a view taken along the line 44 of Figure 2.

The stairway illustrated is of a present day commercial construction. It comprises an endless series of steps In driven atthe upper end of the stairway by means of sprocket wheels through running gear chains, a sprocket wheel and chain being arranged on each side of the stairway. A sprocket wheel I! and running gear chain I2 is illustrated for one side of the stairway. The sprocket wheels are driven by mech-' anism (not shown). 7

Each step is mounted on step brackets ll, one on each side of the stairway. Each step is provided on each side with a chain wheel l8 and a trailerwheel 20 mounted on bracket I'l. These wheels are arranged to run on tracks 2| and 22 respectively. A combplate 23 is provided at the top of the stairway and a similar combplate (not shown) is provided at the bottom of the stairway. The steps emerge from beneath the combplate at the entrance of the stairway in platform formation, transfer to a step formation on the incline of the stairway, change back again to platform formation and pass under the combplate at the exit end of the stairway. v

Referring particularly to Figures 2, 3 and 4, each step comprises a step frame I6 having a riser portion 24 and a tread portion 25. 'Upon the tread portion is mounted a tread plate 26 provided with a plurality of longitudinally extending grooves 27 to form cleats 28. The end 3%] of the tread plate toward the riser of the adjacent'step' is made vertical, this vertical portion extending below the bottoms of the grooves. The body' portion of the tread plate extends out to the end 30 to provide a bottom for the grooves but is cut back slightly for purposes of operating clearance.

The riser portion 24 of the step frame is illustrated as arranged at an'angle to the tread portion and is provided with a curved facing 32 formed with a plurality of vertically extending grooves 33 to provide cleats 34. A liner 35 of sound-deadening material is arranged between the riser facing and the riserportion of the step frame and also between the tread plate and tread portion of the frame. The curvature of the riser cleats is such that the bottoms of the grooves are parallel to the path of movement of the top corner of the cleats of the adjacent step in the transition of that step from step to platform formation and that the top of the riser cleats is parallel to the path of movement of the bottom of the tread grooves at the end of the tread plate of the adjacent step in the transition of that step from step to platform formation. For convenience, the steps shown in Figure, 3 have been designated step No. l and step No. 2. In the case of these steps, for example, the path of movement of the top corner of the end 30 of the tread cleats of step No. 1 is the arc of a circle of a radius equal to the step pitch, 1. e., the distance between adjacent chain wheel axles, and swung from a center at the top corner of the corresponding end 30 of the tread cleats of step No. 2; and the path of movement of the bottom of the tread groove of the end 30 of the tread of step No. 1 is the arc of a circle of the. same radius but swung from a center at the corresponding point on the end 3!! of the tread of step No. 2. The curve of the bottom of the riser groove of step No. 2 and the curve of the topof the riser cleat of step No. 2 are swung from the above centers respectively, the radius in each case being slightly less for purposes of operating clearance. The end 31 of the tread plate of step No. 2 is made the chord of the circle of curvature of the riser grooves, intersecting the circle at the top of the tread plate and the bottom of flange 42 on the tread plate.

With this arrangement, the end of the cleat of each step is maintained at a constant minimum clearance from the riser of the adjacent step both at the top of the tread cleat and the bottom of the end of the tread groove, as the transition from step to platform formation is made. Also, the V groove is eliminated, there being only a small clearance between the step treads when the steps are in platform formation.

The riser facing 32 in the construction illustrated is in the form of a die casting. It is provided with strengthening ribs 38 extending crosswise of the riser and alsovertical strengthening ribs 40. Across the top of the riser facing there is formed a lip portion 4|. This portion hooks in behind flange 42 to secure the facing in place at the top. At the bottom the riser facing is held in .place by means of a clamp 43, a horizontal flange portion 44 being formed on the bottom of the riser facing and being positioned in back of the hooked portion 45 of the clamp. The clamp is tightened in place by means of a bolt 46 which extends through an aperture in the return 41 of step riser portion 24. The end 48 of the clamp opposite the hooked portion is arranged on an angle to slide on the return 41 to clamp the riser into position as the bolt is tightened.

The riser facing illustrated is of pleasing appearance and strong construction, the ribs aiding materially to-strengthen the step, particularly. in preventing the yielding of the steps on the sides.

Other constructions, however, may be employed. For example, the riser portion of the step frame may be curved and a facing provided having cleats formed thereon. This facing may be formed by stamping if desired instead of die casting. Also, the riser portion of the step frame itself may serve as the facing with the cleatsformed therein as by stamping. The cleated riser may also be formed in other ways. i

The cleated riser may be used in conjunction with a shallow grooved tread and short combplate such as disclosed in the co-pending application of Arthur Edward Handy filed January 22, 1938, Serial No, 186,293. By making the depth of the tread cleats say' three-eighths of an inch, the size of the riser cleats may be considerably decreased, thereby facilitating the formation of the riser cleats by stamping.

Although the invention has been described as applied to an ascending moving stairway, it is to be understood that it is equally applicable, to descending stairways and to those which are reversible.

As many changes could be made in the. above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying draw ings shall be interpreted as illustrative andnot in a limiting sense. 1

What is claimed is:

1. In a moving stairway in which each step has a riser and a tread, with the tread provided with a plurality of longitudinally extending grooves to form cleats for meshing with theteeth of a comb at the end of the stairway, the constructionof the steps in which the ends of the cleats of'the tread of each step toward the riser of .the adjacent step when these steps. are in platform formation are substantially parallel to the ends of the cleats of the adjacent step, the grooves between said cleats. being closed at their bottoms out to saidends of the cleats, and in which the riser of each step has a curved face provided with a plurality of upwardly extending curved cleats for meshing with the ends of the tread cleats of the adjacent step while these steps are in step formation and during the transition thereof to platform formation.

2. In a moving stairway in which each step has a riser and a tread, with the tread provided with a plurality of longitudinally extending cleats for meshing with the teeth of a combat the end of the stairway, the construction of the steps in which the ends of the cleats of the tread of each step toward the riser of the adjacent step are'substantially at right angles to the top of the tread, and in which the riser of each step has a curved face provided with a plurality of upwardly extending curved cleats for meshing with the ends of the tread cleats of the adjacent step while these steps are in step formation and during the transition thereof to platform formation, the curvature of said riser face between the cleats and the curvature of the tops of the riser cleats being such as to provide substantially constant operating clearance between the riser and the ends. of the cleats of the adjacent step while the steps are in platform formation and during said transition. I

3. In a moving stairway in which each step has a riser and a tread, with the tread providedwith a plurality of longitudinally extending grooves to form cleats for meshing withthe teeth of a comb at the end of the stairway, the construction of the steps in which the ends of the cleats of the tread of each step toward the riser of the adjacent step are substantially at right angles to the top of the tread, the bottoms of the grooves extending out to said ends of the cleats, and in which the riser of each step has a curved facing provided with a plurality of upwardly extending grooves to form cleats for meshing with the ends of the tread cleats of the adjacent step during the transition of these steps from step to platform formation, the tops of the riser cleats and bottoms of the grooves being of such curvature that the curves intersect at the tread.

4. In a moving stairway in which each step has a curved riser and a tread, with the tread provided with a plurality of longitudinally extending grooves to form cleats for meshing with the teeth of a comb at the end of the stairway, the construction of the steps in which the ends of the cleats of the tread of each step facing the riser of the adjacent step are vertical throughout the height of the cleats, the bottoms of said grooves extending out to said ends of the cleats, and in which the riser of each step is provided with a plurality of upwardly extending grooves to form cleats for meshing with the ends of the tread cleats of the adjacent step during the transition of these steps from step to platform formation, the bottoms of the riser grooves being of .a curvature in accordance with the path of movement of the top of said ends of the tread cleats of the adjacent step during such transition and the vided with a plurality of longitudinally extending grooves to form cleats for meshing with the teeth of a comb at the end of the stairway, the construction of the steps in which the ends of the cleats of the tread of each step facing the riser of the adjacent step are perpendicular to the top of the tread, the bottoms of said grooves extending out to said ends of the cleats, and in which the riser of each step is provided with a plurality of upwardly extending grooves to form cleats for meshing with the ends of the tread cleats of the adjacent step during the transition of these steps from step to platform formation, the bottoms of the riser grooves being of a curvature concentric with the path of movement of the top of said ends of the tread cleats of the adjacent step during such transition, with the size of the curve such as to provide minimum operating clearance therebetween, and the tops of the riser cleats being of a curvature concentric with the path of movement of the bottoms of the grooves of said adjacent step tread at said ends of the tread cleats during such transition, with the size of the curve such as to provide minimum operating clearance therebetween.

6. In a moving stairway in which each step has a curved riser and a tread, with the tread provided with a plurality of longitudinally extending grooves to form cleats for meshing with the teeth of a comb at the end of the stairway, the: construction of the steps in which the end of the cleats of the tread of each step facing the riser of the adjacent step is perpendicular to the top of the tread, the bottom of said grooves extending out to said end of the cleats, and in which the riser of each step is provided with a plurality of upwardly extending grooves to form cleats for meshing with the tread cleats of the adjacent step at said end thereof during the transition of these steps from step to platform formation, the bottom of the riser groovesbeing of a curve swung from the top of said end of the tread cleats and the top of the riser cleats being of a curve swung from the bottom of the grooves of the step tread at said end of the tread cleats, each of said curves being of a radius equal to the step pitch less operating clearance.

DAVID LEONARD LINDQUIST. 

